In the season four opener of Sanctuary, Dr. Helen Magnus has pursued Adam Worth back to 1898 London and must now stop him from altering - and quite possibly completely destroying - the future. Back in present day, Hollow Earth Abnormals continue to reach the surface in droves as the remaining Sanctuary team scrambles to prevent all-out war. At the same time, they are desperate to find Magnus, who was last seen heading to the Hollow Earth city of Praxis just before it was decimated. Season four is a game changer for the Sanctuary, as their allies turn against them and they are forced to make their own rules.